Effect of down-regulated Zfx on human malignant cell line U251 growth. (A) High content cell imaging assays were applied to acquire raw images (unprocessed by software algorithm) of cell growth. (B) Human malignant cell line U251 expressing Zfx-siRNA lentivirus and NC lentivirus were seeded in 96-well plates and cell growth was assayed every day for 5 days. (NC vs Zfx -siRNA, P < 0.05). (C) Cell growth rate was monitored on the 2nd, 3rd, 4th and 5th days by assay. (NC vs Zfx -siRNA, P < 0.05).